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The objective of this work is to prepare biodegradable films of corn starch, replacing a part of the distilled water used in the formulation of the filmogenic solution with an aqueous extract of Hibiscus sabdariffa L. (HSE) and evaluate its functional properties and antimicrobial capacity. The films are made by casting method, adding different HSE:water volume ratios: 100:0, 75:25, 50:50, 25:75, and 0:100 as control. All films with HSE showed an antimicrobial effect, giving positive results against Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli. It is observed that, with the increase in the proportion of HSE, the films are more manageable and glossy than those of starch alone and a more intense red color as the extract content increased, significantly improving its mechanical properties, mainly when the HSE content is above 25% on the filmogenic solution. Likewise, the addition of the extract significantly improved the water vapor barrier capacity of the films. According to the results obtained in this study, corn starch films with aqueous extract of H. sabdariffa are an excellent alternative as a biodegradable packaging material for the food industry, with good functional properties and antimicrobial capacity. [ABSTRACT FROM AUTHOR]

Packaging materials based on biodegradable polymers are a viable alternative to replace conventional plastic packaging from fossil origin. The type of plasticizer used in these materials affects their functionality and performance. The effect of different plasticizers such as glycerol (GLY), sorbitol (SOR), and poly(ethylene glycol) (PEG) in concentrations of 5%, 10%, and 15% (w/w) on the structural features and functional properties of starch/PVOH/chitosan films was evaluated. The incorporation of a plasticizer increased the thickness of the biodegradable composite films. Furthermore, the material plasticized with 30% (w/w) sorbitol had the highest elongation at break, lowest water vapor permeability, and better thermal resistance. The results obtained in this study suggest that maize starch/PVOH/chitosan biodegradable composite films are a promising packaging material, and that sorbitol is the most suitable plasticizer for this formulation. [ABSTRACT FROM AUTHOR]